JMortensen

I'd be really surprised it that caused any problems on the measurement John suggested.

I tried once by driving up a canyon road. Turns out you have to go REALLY fast on a canyon road to put heat in the tires, so I would call my attempt at it unsuccessful. I would do what John suggested, but I'd ride the brake and gas at the same time. That way you don't have to risk getting arrested. Might use up some brakes, but that's not too big an expense.

So what do you do? If you pump it will it just fill back up?

www.betamotorsports.com makes a nice FG (or CF if you have the $$$) hatch.

Definitely need pic of girlfriend to evaluate this situation...

They looked like they were just holes in the fender behind the front wheels, and like I said, the article didn't focus on them, it was focused on the dive planes, but it did say that they cut holes in the body panels with a cutoff wheel, so it didn't sound like any "engineered" attempt to get air out of the engine compartment.

Konis mostly from what I've heard. I don't think they need a revalve, John would know more about that, but I seem to remember that when they last updated the struts they were really valved for stiffer springs anyway... Tom Holt and Cary ran the Ground Control Advance Design struts. I am going to try Bilsteins. I think katman also said they ran Bilsteins with these kinds of rates in the strut thread, and of course I forgot Dan, 74_5.0L_Z as another Z running 400 in/lb springs (Konis I think).

Gotta keep the tires happy. If the tires aren't happy at 350 lbs, then you up the spring rate and do what it takes to make that work. The trend in autox is towards higher spring rates with wide sticky tires. I would love to know what John Thomas is running, but I know Vic Sias ran 400+, Tom Holt is up over 400 if I recall, and from what I gather a bunch of the guys that Cary races with are over 400. I've been picking up a bunch of springs from 500 to 700, going to do some experimenting. I don't think this works on a stock car, but it does if you reinforce the chassis. Is your car still a street car? This is where you start getting into that point where it's not going to be for much longer.

There is an interesting bit in this month's Racecar Engineering about fender vents. Actually it's really about dive planes, but there are about 2 sentences on fender vents that say that they got more downforce from the vents than they did the dive planes, and their vents were apparently "engineered" with a cut off wheel...

Cary has run the limiters on both ends, I believe 74_5.0L_Z did as well. I have made them for both ends but haven't actually run them yet, car is just about to come off of the rotisserie, so I'll be able to tell you how they work in 2027 when the car actually moves under its own power. If you search you'll find my threads on how I did them for my car. The rear came out really good, it's simple out of the way, etc. The front is a bit iffy. It's hard in front because of the steering. I'll have to get everything set up and then make sure there is clearance, but I think it will be OK as it is. Yes, toe is at the tire, or a toe plate which basically is a plate strapped to the tire or bolted to the hub which sticks out front and rear. I don't know about the LSD, to be honest. I think there is a traction advantage to be had with no rear bar (the bar puts a lifting force on the inside rear in order to level the car out). But if you have too much roll by removing the bar, then you might be better off with it on. I would say take one end link off and see what happens, but in order for it to be a fair comparison you'd still have to get the same roll resistance in the rear which means you'd have to up the spring rate to try it in a way that the balance would be the same but the lifting effect of the bar would be neutralized.

The surge tank is cheap. The fuel cell is expensive. The fuel cell is heavy, stock tank is light. The labor to install a cell is pretty substantial. The labor to install a surge pump is pretty minimal. Filling the tank is easier with the stock tank. After installing a cell, the only way I'd suggest it for someone else is if they have to have it by the rules. Without rules requiring the cell, I would avoid it if at all possible. The only thing the cell does better is protect you in the event of a crash, and having been rear ended in a Z by a car that never saw me and hit the back of my car at 50 mph, I'd say that the safety aspect is overrated. YMMV.

These might provide some insight: http://forums.hybrid...nquaiffetorque/ http://forums.hybridz.org/index.php/topic/80753-where-to-focus-to-take-it-to-the-next-performance-level/page__p__766000__hl__%2Bspring+%2Bheavy85__fromsearch__1#entry766000 http://forums.hybridz.org/index.php/topic/70348-poor-wear-on-hoosier-radial-slicks-need-advice/page__p__665785__hl__%2Bspring+%2Bheavy85__fromsearch__1#entry665785

Agreed. The cell will add weight and complexity that isn't needed. A surge tank is pretty easy to do and much simpler. FWIW, when I hear "weight distribution" I think road racing, and for that you really don't want the tank higher up due to the higher cg. You might want it higher for drag racing as that might in theory transfer more weight to the rear axle, but the weight is already in a pretty good spot for drag racing, so the bigger issue is keeping the fuel separated from the passenger compartment, something a lot of drag racers don't seem too concerned with.

Sounds like the pinion bearing spacing is off. That might not be so bad if you can just shim it right. The bigger question is WHY is it off, and if it is off, is the pinion depth also off. I would suggest that you read this manual and get some gear marking compound. Check the pattern and see if the pinion depth is right. If it is, reset the pinion shims to get the correct preload and you should be good to go. If it is wrong, then you'll have to pull the pinion bearing and shim it until it is right. If you get it wrong, the diff will howl. http://www.ringpinion.com/Content/HowTo/TechnicalInstructions/Yukon_Installation_Kit_Instructions.pdf The pilot ball bearing is almost always the one to go bad. If anyone else is thinking of doing this, I'd suggest inspecting the bearings and replacing JUST the pilot if the others look good but it feels like there is sand in there when you turn the pinion with the carrier out. That way you don't get into any of the preload/depth hassle.

I think you're going to be the first. I'll be curious to see what happens to the rear struts if you get traction with that much power. Not that there has been a failure there, but I just don't think it was designed for that. If you do use stock struts, I would suggest www.modern-motorsports.com for stub axles, they make a 39 spline chromoly axle with a CV adapter.

I hate hole saws, but came across and interesting one recently. I was doing some tilework and bought a hole saw to cut through the tiles. It had a plastic guide which came with a couple of double sided tape stickers that attached to the bottom of the guide and the tile. Then the diamond hole saw was stuck into the guide and it simply couldn't wobble around for lack of space. This is SO MUCH BETTER than your traditional hole saw I couldn't believe it. I would imagine that diamond blade would cut through aluminum no problem, haven't tried one on steel, but it wasn't more than $10 at the hardware store, so if you try it and it doesn't work, no big loss. DO NOT use that 25mm drill bit you posted. that will just tear a jagged hole in sheet metal. Here is one like I used: http://www.homedepot.com/h_d1/N-5yc1v/R-202205611/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

I think the reason to run used slicks would be price. If you want to make the most competitive use of your slicks, it will require a lot of changes to the car, probably most notable would be the spring rate. When I ran them I couldn't get them up to temp either (I did see temps in the 180 range as I recall at a track day, operating temp was supposed to be 220 for the tires I was running), and my understanding now is that the spring rate was much too soft. A harder spring works the tire which builds up heat. More grip also equals more roll so more camber loss and worse wear compared to a less sticky tire. Still, I could get a full season of autox and a couple track days out of the Yokohama slicks that I was running. For the price you can't beat them. Goodyear and Hoosier make 16 x 10 slicks in bias ply (more forgiving and requires less neg camber) and radial (more ultimate grip). I'm sure there are others as well: http://www.hoosiertire.com/rrtire.htm http://www.racegoodyear.com/tires/sports.html

Just buy the right sleeve. I am pretty sure www.colemanracing.com has them, and they are not expensive.

I wouldn't buy a 3 year old set of race tires unless they were bagged and treated with VHT or similar. If you're looking for cheap, try used slicks.

Sorry. Let me restate: that would be a shortnose diff. Quite a bit more involved in putting one of those in the car.

tjandriesen, I was just looking at your pictures and it looks like your tubing bender really crushed the tube on the A pillar just above the dash bar. I'm not sure if that will pass tech, but if it does I would suggest you add an "FIA bar". This is a bar that goes from the bottom of the A pillar bar to the halo bar and A pillar junction with no bends. I only say this because if that car goes over I wouldn't trust that crushed tube to keep the roof off of my head. Dash looks nice!

That would be the shortnose R200. Quite a bit more involved in putting one of those in the car.

In terms of lateral acceleration, the wider the better. In terms of longitudinal acceleration you're running a compromise of traction and weight. In terms of wet traction, narrower is better. In terms of top speed, less drag is best. One tire can't do it all and you should fit the tire to its intended usage. If you have a weak motor and you add 20 lbs per corner in wheel weight, you will be able to feel it if you're sensitive to how the car usually drives. All that said If I ran 15x10s I'd be inclined to run the same tires front and back. I don't think you'll gain any handling benefit from running wider rears with your setup as described (you won't be looking for traction with an L24 in all likelihood).

Do some donuts. You won't light both up in that situation unless it's welded or LSD. You could also jack up the rear end and turn the wheels in opposite directions (with a friend). Should take a pretty good effort.

Typically you just get a 2" ID tube and cut it into .5" thick rings, and then weld the rings to the strut tube and set the threaded collars on that.